Eu3+-activated SrMoO4 phosphors for white LEDs applications: Synthesis and structural characterization

Shivakumara, C and Saraf, Rohit (2015) Eu3+-activated SrMoO4 phosphors for white LEDs applications: Synthesis and structural characterization. In: OPTICAL MATERIALS, 42 . pp. 178-186.

PDF opt_mat-42_178_2015.pdf - Published Version Restricted to Registered users only Download (3MB) | Request a copy

Abstract

We report the synthesis of Eu3+-activated SrMoO4 phosphors by the facile nitrate-citrate gel combustion method. Powder XRD and Rietveld refinement data confirmed that these phosphors have a monophasic scheelite-type tetragonal structure with space group I4(1)/a (No. 88). FESEM micrographs indicate the agglomerated spherical particles. FTIR spectra showed four stretching and bending vibrational modes (2A(u) and 2E(u)). UV-Visible absorption spectroscopy illustrated that the optical band gap energy (E-g) values increase with increase in Eu3+ concentration. The host SrMoO4 phosphor exhibited an intense blue emission under UV excitation (368 nm). The Eu3+-activated SrMoO4 phosphors revealed characteristic luminescence due to Eu3+ ion corresponding to D-5(1) -> F-7(J) (J = 1,2) and D-5(0) -> F-7(J) (J = 1,2,3,4) transitions upon 465 nm excitation. The electric dipole transition located at 615 nm (D-5(0) -> F-7(2)) was stronger than the magnetic dipole transition located at 592 nm (D-5(0) -> F-7(1)). Intensity parameters (Omega(2), Omega(4)) and radiative properties such as transition probabilities (A(T)), radiative lifetime (tau(rad)) and branching ratio (beta) of Eu3+-activated SrMoO4 phosphors were calculated using the Judd-Ofelt theory. Based on the CIE chromaticity diagram, these phosphors can be promising materials for the development of blue and orange-red component in white LEDs. (C) 2015 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	OPTICAL MATERIALS
Publisher:	ELSEVIER SCIENCE BV
Additional Information:	Copy right for this article belongs to the Elsevier B.V.
Keywords:	SrMoO4; Gel combustion; Photoluininescence; CIE; Judd-Ofelt analysis; White LEDs
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	28 Apr 2015 07:43
Last Modified:	28 Apr 2015 07:43
URI:	http://eprints.iisc.ac.in/id/eprint/51429

Actions (login required)

View Item